Thermostatically-operated electric switch



Get. 11, 1927.

R. w. McBRIEN THERMOSTATICALLY OPERATED ELECTRIC SWITCH Filed July 15, 1925 Ame/wax;

} mm w. mam/v Amwa Patented Qct. 11, 1927.

PATENT ROGER W. MOBRIEN, 01"" ALTON, ILLINOIS.

THERMOSTA'IICALLY-OPERATED ELECTRIC SWITCH.

Application filed iul 15,

My invention has relation to improvements. in thermostatically operated electric switches and consists in the novel features of construction fully set forth in the specification and pointed out in the claim.

Briefly, the invention consists in providing a receptacle, part of which is-made of insulating material andpart being made of an electric conducting material, within which is a conductor, the end of said conductor being in slightly spaced relation with the conducting part of the receptacle. Placed within the receptacle and normally out of contact with the conductor and metallic part of thereceptacle is a fluent conductor such as mercury which is caused by application of heat to chew e its position so as to short circuit the'con motor and the metallic part of the receptaclethereby clos- 2 ing a suitable signal circuit.

The principal object of the invention is to provide a switch that maybe operated by slight increases in temperature above normal atmospheric temperature so asto close a suitable alarm circuit or any other circuit containing an electrical device that it is desired to bring into operation at such increase in temperature. A- further object is'to provide a switch of this character that is simple in its construction, that may be cheapl manufactured and one that may be repeate f'ly used unless it is subjected to'abnormally high temperatures and destroyed, such as would be the case in event of fire, after the 3? switch had been used to close an electric alarm circuit. Further advantages will be better apparent from a detailed description of the invention in connection with the accompanying drawin s, in which' Figure 1 is a mid le vertical longitudinal section throu h my improved thermostatic switch; and. ig. 2 is an end View thereof;

Referring to the drawings, 1 represents a cylinder, preferably porcelain, rovided with 4 an annular groove 2 near eac 'end thereof and 3, 3 are metallic cones disposed over the ends of the cylinder 1 and crimped into the grooves 2, 2. Thus, the receptacle consists of an intermediate insulated portion, the

c linder 1, and terminal conducting por-.

' tions, the cones 3, 3. At the apex of each cone 3 is a boss 4 projecting from which is a threaded stem 5 to which may be secured a conductor 6 by means of the nut 7 On opposite sides of the cylinder 1 and. medially d sposed are openings 8, 8 through 1925. Serial No. 43,785.

whibhare led conductors 9, 9, one being turned toward one end of the receptacle and terminating in close proximity to one of the cones 3, and the other conductor being turned toward the opposite end of the cylinder and terminating close to the opposite cone 3; After the conductors have been disposed within the receptacle, the openings are roperly sealed'with an insulating materia for a purpose that will presentl appear. Within the receptacle there is inserted a wall 10 of wax or equivalent material which has insulating properties and at the same time fuses at a comparatively low temperature. By comparative low temperature is meant a temperature but slightly above normal atmospheric temperatures; for example, 110 F. Disposed within the receptacle and between the wall of insulating material 10- and one of the cones 3 is a quantity of mercury 11 or some other normall fluent conductor, such as carbon in pulveru ent condition. At each end of the receptacle and secured to each cone 3 is a hanger 12 by which the switch may be supported in the/desired location on a hook or equivalent support. A conductor 13 is connected at one end to conductor 9 and at the 0p osite end to an alarm 14 or other electrical (i being connected by conductor 15 to line wire 16. Connected on the binding post 5- is a conductor 17, said conductor 17 being connected also to the line wire 18, thus the alarm 14 is in series with the conductor 9 and cone 3, and will be actuated on closing the circuit between said conductor and cone.

In operation, the switch is disposed with its longitudinal axis perpendicular, the cones being one above the other and the mercury being held in the upper part of the receptacle by means of the wall of insulatin material 10. If the switch is now subjects to an increase in temperature sufiicient to melt the material 10, obviously the mercury will gravitate to the bottomof the receptacle and the melted wax will float on the top of the body of mercury. As the mercury gathers in the bottom of the rece tacle it will of course make contact with t e bottom cone 3 and lower conductor 9 thusclosin the electric circuit of which these two mem rs form a part and sounding the alarm 14: or o cratin the electrical device that is in thls circult. After the switch has been operated, the mercury has settled to the bottom of the receptacle and the wax on top thereof so evice, said alarm alsothat in order to again operate the switch it ing on the apex of each cone, a pair of will be necessary to invert the same so that con uctors traversing said insulating memthe mercury will again beat the top thereofbet and each terminating adjacent to one of and in contact with the conductor 9 and cone the cones; a fusible insulating wall within 15 6 3 to which the circuit wires have not beeii the insulating member intermediate the connected. ,cones and envelopin said conductors, and a Having described my invention, 1 claim: normally fluent con uctor disposed between A. thermostatic switch consisting of a resaid wall and one of the cones. ceptacle comprising a cyli drical insulating In testimony whereof I hereunto aflix my 20 ROGER w. MoBRIEN.

10 member, a hollow metalli' cone secured to signature.

each end of said insulating inember, a-bind- 

